1. Field of the Invention.
The present invention relates to an improved ion detector and, more specifically, it relates to such a detector which has means which permit the ionizer inlet assembly and the detector assembly to be removed as a unit without meaningful loss of vacuum from the detector.
2.DESCRIPTION OF THE PRIOR ART
The use of mass spectrometers in determining the identity and quantity of constituent materials present in a gaseous, liquid or solid specimen has long been known. It has been known in connection with such systems to, under vacuum, analyze a specimen through conversion of the molecules into ionic form and permitting the ions to bombard a detector. See generally U.S. Pat. Nos. 2,882,410; 3,073,951; 3,590,243; and 4,298,795.
Among the shortcomings of the prior art as exemplified by the hereinbefore identified patents is the fact that they are not designed to have an ionizer inlet assembly probe removed from and introduced into the apparatus without significant loss of vacuum. The same is true with respect to the detector assemblies used in such systems. Replacement of either has generally resulted in a substantial amount of work and a significant loss of time.
While U.S. Pat. No. 4,454,894 discloses a gas bleed cock, there is lacking in the present environment a teaching of a system which permits elimination of certain portions of a specimen such as a carrier gas, such as helium, prior to introduction of the specimen into the ionizer. There is also lacking a system which permits precise control and adjustment of such discharge apparatus.
There remains, therefore, a very real and substantial need for an improved ion detector and for such a detector which permits removal of components without undesired loss of vacuum.